splitting of heart sounds

Definition: the production of major components of the first and second heart sounds (rarely the third and fourth) due to contribution by the left-sided and right-sided valves; thus, the first heart sound would have a mitral and a tricuspid component and the second heart sound an aortic and pulmonic component. The latter are best appreciated during respiration, with inspiration delaying the pulmonic component and producing an earlier aortic component.